An operator of a vehicle may use a mobile device to perform a variety of vehicle functions. For example, the mobile device may communicate with the vehicle to start the vehicle or unlock a vehicle door. It is desirable to be able to perform these and other vehicle functions based in part on the operator's proximity to the vehicle. The mobile device may communicate with a backend system which may send a cellular message to the vehicle thereby starting the vehicle or unlocking the door. In some instances, cellular service may be unavailable. Hence, there is a need to provide a means to provide such services to the user in the absence of cellular communication.